They have to come up with the equations? Do you mean they are given a word problem and they have to solve it? I know I am getting old, your number one and two were confusing and unclear to me and I have a business degree. LOL.
I’m think with the terms I would explain all the terms, they can also have them listed as vocabulary to memorize. I would do a worksheet where they label or match up what is a premium what is the interest in and also multiple choice. Doesn’t the text book have a workbook with it? Or, problems at the end of the chapter?
Have them read a credit card statement, so it is like real life, and answer questions regarding the statement. I think a law passed where it says on the statement what it costs over time if you don’t pay in full? I never look over that part of the statement so I don’t know off the top of my head if it really is on there.
They can also figure out mortgage payments.
They can look at a savings account statement and interpret that too.